Add delay to hopper even if it doesn't do anything. Fixes BUKKIT-4061

If a hopper is unable to perform any action during a tick it attempts to do
so every tick from then on. Once it is able to do so it then sets a delay
before attempting to do something again. To avoid excessive CPU usage for
hoppers sitting idle we now apply this delay regardless of the success of
the action.

src/main/java/net/minecraft/server/TileEntityHopper.java

@@ -180,8 +180,11 @@ public class TileEntityHopper extends TileEntity implements IHopper {
             if (!this.l() && BlockHopper.d(this.p())) {
                 boolean flag = this.u() | suckInItems(this);
 
+                // CraftBukkit start - Move delay out of if block
+                this.c(8);
+
                 if (flag) {
-                    this.c(8);
+                    // CraftBukkit end
                     this.update();
                     return true;
                 }